The sidewalk outside Systems Technology, Inc. in Hawthorne, California, feels solid. Or so my senses tell me. Only moments ago, they told me I was plummeting earthward from about 5,000 feet. The skydiving simulator, called PARASIM, takes you from the ground to “Geronimo!” without making you bail out of a perfectly good airplane. “This is not a game,” STI president and CEO Dave Landon says. “This is the only parachute simulator in the U.S. We hold the patent.”

STI began training skydivers 20 years ago, when the U.S. Forest Service asked for help in reducing smoke jumper injuries. Today, U.S. Special Forces does dry-run jumps integrating parachute malfunctions, challenging terrain, and weather complications—minus the considerable expense of a real aircraft. Simulators can be networked so team members appear as full-motion avatars on one another’s helmet-mounted virtual displays. Worldwide, 400 PARASIMs are in use.

Buckled into a harness that lets me experience the posture of a free fall, I’m suspended horizontally beneath a 10-foot-tall frame. An instructor at a computer terminal calls “Jump.” I plunge into the clear blue, somewhere above artificial Fort Bragg. My helmet screen shows the altitude reading from an altimeter strapped to my virtual wrist. PARASIM senses and converts body motions into aerodynamic-appropriate responses. “You can turn, you can track, you can slide or just stay in a steady state,” Landon explains. Somewhere in the real world, I hear the word “ripcord” and pull the metal handle. Pulleys release me into a vertical feet-first posture, and my instructor reminds me to check the parachute. Beneath the canopy, I work the steering toggles. PARASIM responds smartly. The landing target approaches, just beyond two tall trees.

“The airflow is modeled exactly as it is in reality,” Landon says. “As you free fall in the simulator, so will you fall in real life.”